import pygame,time pygame.init() screen = pygame.display.set_mode([900, 700]) pygame.display.est_caption(弹球) red = 255,0,0 black = 0,0,0 x = 10 y = 10 dx = 2 dy = 1 redius = 10 KeepGoing = True whil

e KeepGoing:
for event in pygame.event.get():
if event.type == pygame.QUIT:
KeepGoing = False

screen.fill(black)
pygame.draw.circle(screen, red, (x, y), radius)
pygame.display.flip()

x += dx
y += dy

if x + radius > 900 or x - radius < 0:
dx *= -1
if y + radius > 700 or y - radius < 0:
dy *= -1

time.sleep(0.01)

pygame.quit()